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Algae Harvesting using Dissolved Air Floatation

One of the biggest problem in algae biofuels commercialization lies in the process of algae harvesting. This post features a technology which has been used by the University of California. The San Diego Center for Algal Biotechnology (SD-CAB) , of the University of California, has been doing algae biofuel research since 2008, together with the Scripps Institution of Oceanography.

The research colloboration has utilized a harvest system which processes up to 9000 gallons of algae-laden water per minute at a 95% capture rate, yielding up to 20% algae concentrations. The algae harvesting technology is being brought by a company called World Water Works which uses optimized dissolved air flotation system to harvest the algae from water.

How the technology works?

Pond water is pumped into the DAF where suspended solids in the form of algae are separated from the water by a process of dissolving air into the water under pressure, with the addition of a polyacrylamide flocculent. Upon release of that pressure, microbubbles form. These microbubbles interact with the algae particles, attaching to the biomass surface and affecting the particle density, causing them to float to the surface of the DAF. They are then skimmed with a chain and flight mechanism to a sieved Thickening Beach (trademarked). The Thickening Beach allows free water to be drained and thickens the algae particles, achieving an efficient liquids and biomass separation.

Patented Nikuni air dissolving technology is used to create the robust whitewater in the AHTO system, which saturates the effluent pond water entering the DAF with atmospheric air.

Heavy sand and grit particles settle to the bottom, where a timer function controls the removal. The clean water is continuously removed from the DAF and piped back into the ponds, allowing new pond water laden with algae to enter for separation.

Source: http://ese.dgtlpub.com/2013/2013-02-28/pdf/Dissolved_air_flotation_process_harvests_algae_for_biodiesel_research.pdf

Mon July 22 2013 07:00:34 AM by Sindhuja Dissolved Air Floatation  |  DAF  |  algae harvesting 2623 views
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